What kind of rocks and how does a person use it?

Man has the ability to use many breeds. Graphite. It is used for pencils. And also it is used in nuclear reactors, to control their power, it plays a very important role, and it can also form into a diamond from high temperatures, this happens naturally, or artificially. Salt. It is used to improve the taste of food, but before it is consumed, it is cleaned of impurities, iodine is added, making it iodized, and can be consumed.